Question

Hi,

I need help to finish this program.

Thank you

import java.io.FileNotFoundException;
import javax.swing.JFrame;

/**
* The Main class containing the main() and run() methods.
*/
public class Main {
  
public static void main(String[] pArgs) {
   new Main().run();
}

/**
* The Roster of students that is read from the input file "gradebook.dat".
*/
  
???

/**
* A reference to the View object.
*/
???

/**
* This is where execution starts. Instantiate a Main object and then call run().
*/
???

/**
* exit() is called when the Exit button in the View is clicked. When we exit we have to write
* the roster to the output file "gradebook.dat". Then we exit the program with a code of 0.
*
* We open the file and write the roster to it in a try-catch block, where we catch a
* FileNotFoundException that will be thrown if for some reason, we cannot open "gradebook.dat"
* for writing.
*
* PSEUDOCODE:
* method exit() : void
* try
* instantiate a GradebookWriter object named gbWriter, opening "gradebook.dat" for
* writing
* call writeGradebook(getRoster()) on gbWriter
* call System.exit(0) to terminate the application with an exit code of 0
* catch FileNotFoundException e
* call messageBox() on getView() to display a message box containing the text "Could
* not open gradebook.dat for writing. Exiting without saving."
* call System.exit(-1) to terminate the application with an error code of -1
* end try-catch
* end exit
*/
  
private void run(){
   JFrame.setDefaultLookAndFeelDecorated(true);
   setView(new View(this));
   try {
GradebookReader gradeBook = new GradebookReader("gradebook.txt");
setRoster(gradeBook.readGradebook());
mRoster = getRoster();

} catch (FileNotFoundException pException) {
getView().messageBox("Could not open gradebook.txt for reading. Exiting.");
System.exit(-1);
}
}

/**
* This method returns the number of exams in the class.
*/
???

/**
* This method returns the number of homework assignments in the class.
*/
???
  
/**
* Accessor method for mRoster.
*/
private Roster getRoster() {
return mRoster;
}

/**
* Accessor method for mView.
*/
private View getView() {
return mView;
}

/**
* run() is the main routine and is called from main().
*
* PSEUDOCODE:
* method run
* call JFrame.setDefaultLookAndFeelDecorated(true or false depending on your preference)
* -- Create the View passing 'this' as the argument so the View will be linked to the Main
* -- class so they may communicate with each other. Then pass the newly created View object
* -- to setView() to save the reference to the View in our instance variable mView.
* call setView(new View(this)) to create the View and stored the returned object in mView
* try
* -- Note that when we try to open "gradebook.dat" for reading that GradebookReader()
* -- may throw a FileNotFoundException which we catch here.
* create a GradbookReader object named gbReader opening "gradebook.dat" for reading
* -- Read the student roster from the input file.
* call readGradebook() on gbReader, which returns the Roster
* call setRoster() on the Roster returned from readGradebook() to save the roster in
* our instance variable mRoster
* catch
* call messageBox() on getView() to display the error message "Could not open
* gradebook.dat for reading. Exiting."
* call System.exit(-1) to terminate the application with an exit code of -1
* end try-catch
* end run
*/
  
private void run(){
   JFrame.setDefaultLookAndFeelDecorated(true);
   setView(new View(this));
   try {
GradebookReader gradeBook = new GradebookReader("gradebook.txt");
setRoster(gradeBook.readGradebook());
mRoster = getRoster();

} catch (FileNotFoundException pException) {
getView().messageBox("Could not open gradebook.txt for reading. Exiting.");
System.exit(-1);
}
}

/**
* search() is called when the Search button is clicked in the View. The input parameter is
* the last name of the Student to search the roster for. Call getStudent(pLastName) on the
* Roster object (call getRoster() to get the reference to the Roster) to get a reference to
* the Student with that last name. If the student is not located, getStudent() returns null.
*
* @param pLastName The last name of the student who we will search the Roster for.
*
* PSEUDOCODE:
* method search(pLastName : String) : Student
* call getRoster().getStudent(pLastName) and return what getStudent() returns
* end search
*/
public Student search(String pLastName) {
return getRoster().getStudent(pLastName);
}

/**
* Mutator method for mRoster.
*/
private void setRoster(Roster pRoster) {
mRoster = pRoster;
}

/**
* Mutator method for mView.
*/
private void setView(View pView) {
mView = pView;
}
}

Answer 1

Main.java

import java.io.FileNotFoundException;
import javax.swing.JFrame;

/**
* The Main class containing the main() and run() methods.
*/
public class Main {

    // The Roster of students that is read from "gradebook.txt".
    private Roster mRoster;

    // A reference to the View object.
    private View mView;

    /**
     * This is where execution starts. Instantiate a Main object and then call run().
     */
    public static void main(String[] pArgs) {
        Main main = new Main();
        main.run();
    }

    /**
     * exit() is called when the Exit button in the View is clicked.
     *
     * PSEUDOCODE:
     * try
     *     Instantiate a GradebookWriter object opening "gradebook.txt" for writing
     *     Call writeGradebook(getRoster()) on the object
     *     Call System.exit(0) to terminate the application
     * catch FileNotFoundException
     *     Call messageBox() on the View to display ""Could not open gradebook.txt for writing. Exiting without saving."
     *     Call System.exit(-1) to terminate the application with an error code of -1
     */
    public void exit(){
       try{
           GradebookWriter gbWriter = new GradebookWriter("gradebook.txt");
           gbWriter.writeGradebook(getRoster());
           System.exit(0);
           gbWriter.close();
       }
       catch (FileNotFoundException fnfe){
           getView().messageBox("Could not open gradebook.txt for writing. Exiting without saving.");
           System.exit(-1);
       }
    } //END OF exit()

    /**
     * Accessor method for mRoster.
     */
    public Roster getRoster() {
        return mRoster;
    }

    /**
     * Accessor method for mView.
     */
    public View getView() {
        return mView;
    }

    /**
     * run() is the main routine.
     *
     * PSEUDOCODE:
     * Call JFrame.setDefaultLookAndFeelDecorated(true or false depending on your preference)
     * Call setView(instantiate new View object passing this to the ctor)
     * try
     *     Instantiate a GradebookReader object to open "gradebook.txt" for reading
     *     Call readGradebook() on the object
     *     Call setRoster() to save the Roster returned from readGradebook()
     * catch
     *     Call messageBox() on the View to display "Could not open gradebook.txt for reading. Exiting."
     *     Call System.exit(-1) to terminate the application with an error code
     */
    private void run(){
       JFrame.setDefaultLookAndFeelDecorated(false);
       setView(new View(this));
      
       try{
           GradebookReader gbReader = new GradebookReader("gradebook.txt");
           setRoster(gbReader.readGradebook());
       }
       catch (FileNotFoundException fnfe){
           getView().messageBox("Could not open gradebook.txt for reading. Exiting.");
           System.exit(-1);
       }
    } //END OF run()

    /**
     * search() is called when the Search button is clicked on the View. The input parameter is the non-empty last name
     * of the Student to locate. Call getStudent(pLastName) on the Roster object to get a reference to the Student with
     * that last name. If the student is not located, getStudent() returns null.
     */
    public Student search(String pLastName){
       return getRoster().getStudent(pLastName);
    } //END OF search()

    /**
     * Mutator method for mRoster.
     */
    public void setRoster(Roster pRoster) {
        mRoster = pRoster;
    }

    /**
     * Mutator method for mView.
     */
    public void setView(View pView) {
        mView = pView;
    }
} //END OF Main CLASS

Roster.java

import java.util.ArrayList;

/**
* The Roster class encapsulates an ArrayList<Student> which stores the information for each student in the gradebook.
*/
public class Roster {

    // Declare mStudentList
    ArrayList<Student> mStudentList;

    /**
     * Roster()
     *
     * PSEUDOCODE:
     * Create mStudentList.
     */
    public Roster(){
       mStudentList = new ArrayList<Student>();
    }

    /**
     * addStudent()
     *
     * PSEUDOCODE:
     * Add (append) pStudent to mStudentList.
     */
    public void addStudent(Student pStudent){
       getStudentList().add(pStudent);
    }

  
    public Student getStudent(String pLastName){
       int index = Searcher.search(getStudentList(), pLastName);
      
       if (index == -1){
           return null;
       }
       else{
           return getStudentList().get(index);
       }
    } //END OF getStudent()

    /**
     * getStudentList()
     * Accessor method for mStudentList.
     */
    public ArrayList<Student> getStudentList() {
        return mStudentList;
    }

    /**
     * setStudentList()
     * Mutator method for mStudentList.
     */
    private void setStudentList(ArrayList<Student> pStudentList) {
        mStudentList = pStudentList;
    }

    public void sortRoster(){
       Sorter.sort(getStudentList());
    }

    /**
     * Returns a String representation of this Roster. Handy for debugging.
     */
    @Override
    public String toString() {
        String result = "";
        for (Student student : getStudentList()) result += student + " ";
        return result;
    } //END OF toString()
} //END OF Roster CLASS

Student.java

import java.util.ArrayList;

/**
* The Student class stores the grade information for one Student.
*/
public class Student implements Comparable<Student> {

    // Declare the instance variables.
    ArrayList<Integer> mExamList;
    ArrayList<Integer> mHomeworkList;
    String mFirstName;
    String mLastName;

    /**
     * Student()
     *
     * PSEUDOCODE:
     * Save pFirstName and pLastName.
     * Create mExamList
     * Create mHomeworkList
     */
     public Student(String pFirstName, String pLastName){
       mFirstName = pFirstName;
       mLastName = pLastName;
       mExamList = new ArrayList<Integer>();
       mHomeworkList = new ArrayList<Integer>();
     } //END OF Student() <<ctor>>

    /**
     * addExam()
     *
     * PSEUDOCODE:
     * Call add(pScore) on getExamList() to add a new exam score to the list of exam scores.
     */
    public void addExam(int pScore){
       getExamList().add(pScore);
    }

    /**
     * addHomework()
     *
     * PSEUDOCODE:
     * Call add(pScore) on getHomeworkList() to add a new homework score to the list of homework scores.
     */
    public void addHomeWork(int pScore){
       getHomeworkList().add(pScore);
    }

    /**
     * compareTo()
     *
     * PSEUDOCODE:
     * Return: -1 if the last name of this Student is < the last name of pStudent
     * Return: 0 if the last name of this Student is = the last name of pStudent
     * Return: 1 if the last name of this Student is > the last name of pStudent
     * Hint: the last names are Strings.
     */
    public int compareTo(Student pStudent){
       return (this.getLastName()).compareTo(pStudent.getLastName());
    }

    /**
     * getExam()
     *
     * Accessor method to retreive an exam score from the list of exams.
     */
    public int getExam(int pNum) {
        return getExamList().get(pNum);
    }

    /**
     * getExamList()
     *
     * Accessor method for mExamList.
     */
    protected ArrayList<Integer> getExamList() {
        return mExamList;
    }

    /**
     * getFirstName()
     *
     * Accessor method for mFirstName.
     */
    public String getFirstName() {
        return mFirstName;
    }

    /**
     * getHomework()
     *
     * Accessor method to retrieve a homework score from the list of homeworks.
     */
    public int getHomework(int pNum) {
        return getHomeworkList().get(pNum);
    }

    /**
     * getHomeworkList()
     *
     * Accessor method for mHomeworkList.
     */
    protected ArrayList<Integer> getHomeworkList() {
        return mHomeworkList;
    }

    /**
     * getLastname()
     *
     * Accessor method for mLastName.
     */
    public String getLastName() {
        return mLastName;
    }

    /**
     * setExam()
     *
     * Mutator method to store an exam score into the list of exam scores.
     */
    public void setExam(int pNum, int pScore) {
        getExamList().set(pNum, pScore);
    }

    /**
     * setExamList()
     *
     * Mutator method for mExamList.
     */
    protected void setExamList(ArrayList<Integer> pExamList) {
        mExamList = pExamList;
    }

    /**
     * setFirstName()
     *
     * Mutator method for mFirstName.
     */
    public void setFirstName(String pFirstName) {
        mFirstName = pFirstName;
    }

    /**
     * setHomework()
     *
     * Mutator method to store a homework score into the list of homework scores.
     */
    public void setHomework(int pNum, int pScore) {
        getHomeworkList().set(pNum, pScore);
    }

    /**
     * setHomeworkList()
     *
     * Mutator method for mHomeworkList.
     */
    protected void setHomeworkList(ArrayList<Integer> pHomeworkList) {
        mHomeworkList = pHomeworkList;
    }

    /**
     * setLastname()
     *
     * Mutator method for mLastName.
     */
    public void setLastName(String pLastName) {
        mLastName = pLastName;
    }

    /**
     * toString()
     *
     * Returns a String representation of this Student. The format of the returned string shall be such that the Student
     * information can be printed to the output file, i.e:
     *
     * lastname firstname hw1 hw2 hw3 hw4 exam1 exam2
     */
    @Override
    public String toString(){
       String str = this.getLastName()+ " " + this.getFirstName() + " ";
      
       for (int i = 0; i < getHomeworkList().size(); i++){
           str += getHomework(i) + " ";
       }
      
       for (int i = 0; i < getExamList().size(); i++){
           str += getExam(i) + " ";
       }
       return str.trim();
    } //END OF toString()
} //END OF Student CLASS

View.java

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

/**
* The View class implements the GUI.
*/
public class View extends JFrame implements ActionListener {

    /**
   * Serial version for View
   */
   private static final long serialVersionUID = 1L;
  
   public static final int FRAME_WIDTH = 500;
    public static final int FRAME_HEIGHT = 250;

    // Declare instance variables
    private JButton mClearButton;
    private JTextField[] mExamText;
    private JButton mExitButton;
    private JTextField[] mHomeworkText;
    private Main mMain;
    private JButton mSearchButton;
    private JButton mSaveButton;
    private JTextField mSearchText;
    private Student mStudent;

    /**
     * View()
     *
     * The View constructor creates the GUI interface and makes the frame visible at the end.
     */
    public View(Main pMain) {

        // Save a reference to the Main object pMain in mMain.
        mMain = pMain;

        JPanel panelSearch = new JPanel();
        panelSearch.add(new JLabel("Student Name: "));
        mSearchText = new JTextField(25);
        panelSearch.add(mSearchText);
        mSearchButton = new JButton("Search");
        mSearchButton.addActionListener(this);
        panelSearch.add(mSearchButton);

        // PSEUDOCODE:
        // Create a JPanel named panelHomework which uses the FlowLayout.
        // Add a JLabel "Homework: " to the panel
        // Create mHomeworkText which is an array of CourseConstants.NUM_HOMEWORKS JTextFields
        // For i = 0 to CourseConstants.NUM_HOMEWORKS - 1 Do
        //     Create textfield mHomeworkText[i] displaying 5 cols
        //     Add mHomeworkText[i] to the panel
        // End For
        JPanel panelHomework = new JPanel();
        panelHomework.add(new JLabel("Homework: "));
        mHomeworkText = new JTextField[CourseConstants.NUM_HOMEWORKS];
        for (int i = 0; i < CourseConstants.NUM_HOMEWORKS; i++){
           mHomeworkText[i] = new JTextField(5);
           panelHomework.add(mHomeworkText[i]);
        }

        // Create the exam panel which contains the "Exam: " label and the two exam text fields. The pseudocode is omitted
        // because this code is very similar to the code that creates the panelHomework panel.
        JPanel panelExam = new JPanel();
        panelExam.add(new JLabel("Exam: "));
        mExamText = new JTextField[CourseConstants.NUM_EXAMS];
        for (int i = 0; i < CourseConstants.NUM_EXAMS; i++){
           mExamText[i] = new JTextField(5);
           panelExam.add(mExamText[i]);
        }

        // PSEUDOCODE:
        // Create a JPanel named panelButtons using FlowLayout.
        // Create the Clear button mClearButton.
        // Make this View the action listener for mClearButton.
        // Add the Clear button to the panel.
        // Repeat the three above statements for the Save button.
        // Repeat the three above statements for the Exit button.
        JPanel panelButtons = new JPanel();
        mClearButton = new JButton("Clear");
        mClearButton.addActionListener(this);
        panelButtons.add(mClearButton);
        mSaveButton = new JButton("Save");
        mSaveButton.addActionListener(this);
        panelButtons.add(mSaveButton);
        mExitButton = new JButton("Exit");
        mExitButton.addActionListener(this);
        panelButtons.add(mExitButton);

        // PSEUDOCODE:
        // Create a JPanel named panelMain using a vertical BoxLayout.
        // Add panelSearch to panelMain.
        // Add panelHomework to panelMain.
        // Add panelExam to panelMain.
        // Add panelButtons to panelMain.
        JPanel panelMain = new JPanel();
        panelMain.setLayout(new BoxLayout(panelMain, BoxLayout.Y_AXIS));
        panelMain.add(panelSearch);
        panelMain.add(panelHomework);
        panelMain.add(panelExam);
        panelMain.add(panelButtons);

        // Initialize the remainder of the frame, add the main panel to the frame, and make the frame visible.
        setTitle("Gradebookulator");
        setSize(FRAME_WIDTH, FRAME_HEIGHT);
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        add(panelMain);
        setVisible(true);
      
        //----EXTRA: Added this line of code to set the GUI to the middle of the screen---
        setLocationRelativeTo(null);
    } //END OF View() <<ctor>>

    public void actionPerformed(ActionEvent pEvent){
       if (pEvent.getSource() == mSearchButton){
           String lastName = mSearchText.getText();
          
           if (lastName.isEmpty()){
               messageBox("Please enter the student's last name.");
           }
           else{
               mStudent = mMain.search(lastName);
               if (mStudent == null){
                   messageBox("Student not found. Try again.");
               }
               else{
                   displayStudent(mStudent);
               }
           }
       }
       else if (pEvent.getSource() == mSaveButton){
           if (mStudent != null){
               saveStudent(mStudent);
           }
       }
       else if (pEvent.getSource() == mClearButton){
           clear();
       }
       else if (pEvent.getSource() == mExitButton){
           if (mStudent != null){
               saveStudent(mStudent);
           }
           mMain.exit();
       }
    }//END OF actionPerformed()

    /**
     * clear()
     *
     * Called when the Clear button is clicked. Clears all of the text fields by setting the contents to the empty string.
     * After clear() returns, no student information is being edited or displayed.
     *
     * PSEUDOCODE:
     * Set the mSearchText text field to ""
     * Set each of the homework text fields to ""
     * Set each of the exam text fields to ""
     * Set the mStudent reference to null
     */
    private void clear(){
       mSearchText.setText("");
       for (int i = 0; i < mHomeworkText.length; i++){
           mHomeworkText[i].setText("");
       }
       for (int i = 0; i < mExamText.length; i++){
           mExamText[i].setText("");
       }
       mStudent = null;
    } //END OF clear()

    /**
     * displayStudent()
     *
     * Displays the homework and exam scores for a student in the mHomeworkText and mExamText text fields.
     *
     * PSEUDOCODE:
     * For i = 0 to CourseConstants.NUM_HOMEWORKS - 1 Do
     *     int hw = pStudent.getHomework(i)
     *     String hwstr = convert hw to a String (Hint: Integer.toString())
     *     mHomeworkText[i].setText(hwstr)
     * End For
     * Write another for loop similar to the one above to place the exams scores into the text fields
     */
    private void displayStudent(Student pStudent){
       for (int i = 0; i < CourseConstants.NUM_HOMEWORKS; i++){
           int hw = pStudent.getHomework(i);
           String hwstr = Integer.toString(hw);
           mHomeworkText[i].setText(hwstr);
       }
       for (int i = 0; i < CourseConstants.NUM_EXAMS; i++){
           int exam = pStudent.getExam(i);
           String examstr = Integer.toString(exam);
           mExamText[i].setText(examstr);
       }
    }//END OF displayStudent()

    /**
     * messageBox()
     *
     * Displays a message box containing some text.
     */
    public void messageBox(String pMessage) {
        JOptionPane.showMessageDialog(this, pMessage, "Message", JOptionPane.PLAIN_MESSAGE);
    } //END OF messageBox()

    /**
     * saveStudent()
     *
     * Retrieves the homework and exam scores for pStudent from the text fields and writes the results to the Student record
     * in the Roster.
     *
     * PSEUDOCODE:
     * For i = 0 to CourseConstants.NUM_HOMEWORKS - 1 Do
     *     String hwstr = mHomeworkText[i].getText()
     *     int hw = convert hwstr to an int (Hint: Integer.parseInt())
     *     Call pStudent.setHomework(i, hw)
     * End For
     * Write another for loop similar to the one above to save the exam scores
     */
    private void saveStudent(Student pStudent){
       for (int i = 0; i < CourseConstants.NUM_HOMEWORKS; i++){
           String hwstr = mHomeworkText[i].getText();
           int hw = Integer.parseInt(hwstr);
           pStudent.setHomework(i, hw);
       }
       for (int i = 0; i < CourseConstants.NUM_EXAMS; i++){
           String examstr = mExamText[i].getText();
           int exam = Integer.parseInt(examstr);
           pStudent.setExam(i, exam);
       }
    }//END OF saveStudent()
  
}//END OF View CLASS

CourseConstants.java

public class CourseConstants {

    public static final int NUM_EXAMS     = 2;
    public static final int NUM_HOMEWORKS = 4;

}

Searcher.java

import java.util.ArrayList;

public class Searcher{
  
   public static int search(ArrayList<Student> pList, String pKey){
       int low = 0;
       int high = pList.size() - 1;
      
       while (low <= high){
           int middle = (low + high) / 2;
           if (pList.get(middle).getLastName().equalsIgnoreCase(pKey)){
               return middle;
           }
           else if ((pList.get(middle).getLastName()).compareToIgnoreCase(pKey) < 0){
               low = middle + 1;
           }
           else {
               high = middle - 1;
           }
       } //END OF while loop
      
       return -1;
   } //END OF search()
}//END OF Searcher CLASS

Sorter.java

import java.util.ArrayList;
import java.util.Collections;

public class Sorter {
  
   private static int partition(ArrayList<Student> pList, int pFromIdx, int pToIdx){
       Student pivot = pList.get(pFromIdx);
       int leftIndex = pFromIdx - 1;
       int rightIndex = pToIdx + 1;
      
       while(leftIndex < rightIndex){
          
           leftIndex++;
           while (pList.get(leftIndex).compareTo(pivot) < 0){
               leftIndex++;
           }
          
           rightIndex--;
           while(pList.get(rightIndex).compareTo(pivot) > 0){
               rightIndex--;
           }
          
           if (leftIndex < rightIndex){
               swap(pList, leftIndex, rightIndex);
           }
       }//END OF while LOOP
       return rightIndex;
   } //END OF partition()
  
   private static void quickSort(ArrayList<Student> pList, int pFromIdx, int pToIdx){
       if (pFromIdx >= pToIdx){
           return;
       }
      
       int partitionIndex = partition(pList, pFromIdx, pToIdx);
      
       quickSort(pList, pFromIdx, partitionIndex);
       quickSort(pList, partitionIndex + 1, pToIdx);
   } //END OF quickSort()
  
   public static void sort(ArrayList<Student> pList){
       quickSort(pList, 0, pList.size() - 1);
   } //END OF sort()
  
   private static void swap(ArrayList<Student> pList, int pIdx1, int pIdx2){
       Collections.swap(pList, pIdx1, pIdx2);
   } //END of swap()
} //END OF Sorter CLASS

GradebookWriter.java

import java.io.FileNotFoundException;
import java.io.PrintWriter;

/**
* GradebookWriter inherits from PrintWriter and writes the gradebook info to the file name passed to the ctor.
*/
public class GradebookWriter extends PrintWriter {

    /**
     * GradebookWriter()
     * Call the super class ctor that takes a String.
     */
    public GradebookWriter(String pFname) throws FileNotFoundException{
       super(pFname);
    }

    /**
     * writeGradebook()
     * Writes the gradebook info to the file, which was opened in the ctor.
     *
     * PSEUDOCODE:
     * EnhancedFor each student in pRoster.getStudentList() Do
     *    Call println(student)
     * End For
     * Call close()
     */
    public void writeGradebook(Roster pRoster){
       for (Student student : pRoster.getStudentList()){
           println(student);
       }
       close();
    }//END OF writeGradebook()
} //END OF GradebookWriter CLASS

GradebookReader.java

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

/**
* GradebookRead reads the gradebook info from the file name passed to the ctor.
*/
public class GradebookReader {

    private Scanner mIn;

    /**
     * Attempts to open the gradebook file for reading. If successful, mIn will be used to read from the file. If the file
     * cannot be opened, a FileNotFoundException will be thrown.
     */
    public GradebookReader(String pFname) throws FileNotFoundException {
        mIn = new Scanner(new File(pFname));
    }

    /**
     * Reads the exam scores for a Student.
     */
    private void readExam(Student pStudent) {
        for (int n = 0; n < CourseConstants.NUM_EXAMS; ++n) {
            pStudent.addExam(mIn.nextInt());
        }
    }

    /**
     * Called to read the gradebook information. Calls readRoster() to read the student records and then sorts the roster
     * by last name.
     */
    public Roster readGradebook() {
        Roster roster = readRoster();
        roster.sortRoster();
        return roster;
    }

    /**
     * Reads the homework scores for a Student.
     */
    private void readHomework(Student pStudent) {
        for (int n = 0; n < CourseConstants.NUM_HOMEWORKS; ++n) {
            pStudent.addHomeWork(mIn.nextInt());
        }
    }

    /**
     * Reads the student information from the input file adding Student objecs to the roster.
     */
    private Roster readRoster() {
        Roster roster = new Roster();
        while (mIn.hasNext()) {
            String lastName = mIn.next();
            String firstName = mIn.next();
            Student student = new Student(firstName, lastName);
            readHomework(student);
            readExam(student);
            roster.addStudent(student);
        }
        return roster;
    }
}

gradebook.txt
Bouvier Selma 16 16 16 16 16 16
Explosion Nathan 5 4 3 2 1 0
Flanders Ned 12 14 17 23 85 95
Flintstone Fred 40 31 35 35 98 100
Jetson George 20 21 22 23 70 83
Muntz Nelson 20 15 10 5 60 70
Simpson Lisa 30 30 25 25 100 100
Skinner Seymour 19 23 21 24 78 83
Spuckler Cletus 1 2 3 4 5 6
Terwilliger Robert 23 21 19 17 80 90
Wiggum Clancy 6 5 4 3 2 1